A recent report published in JAMA Internal Medicine found that contamination of skin and clothing occurs during glove and gown removal in 60% of cases (M E Tomas, et al. (2015). Contamination of Health Care Personnel During Removal of Personal Protective Equipment. JAMA Intern Med. 175(12):1904-10.) When using educational intervention and visual feedback, the study found that the rate of contamination fell to 18.9%. However, providing training on proper personal protective equipment removal is not always feasible, especially in resource-limited settings or during epidemics, and many commonly used disinfectants do not provide visual feedback. Thus, there exists a need for improved methods and techniques to visually ensure proper disinfection to reduce the rate of contamination.
Commercially available products such as Glo Germ™ have demonstrated the importance of visualizing disinfection. For instance, Glo Germ™ has been used in the Mount Sinai Health System to ensure that surfaces are completely disinfected (The Wall Street Journal. (2015, Nov. 2)). However, Glo Germ™ requires the use of an ultraviolet light for visualization, which may not be readily available in the field, and requires a power source. In addition, the need to carry around or install an ultraviolet light source can be tedious and infeasible for checking every disinfected surface in a fast-paced hospital setting.
Further studies have also demonstrated that improving compliance with waiting sufficient contact time for a disinfectant to inactivate a pathogen can reduce the rate of hospital-acquired infections by more than 80% (R Orenstein, et al. (2011). Infect Control Hosp. Epidemiol. 32(11): 1137-9.) This strongly suggests that a method for improving compliance with contact time is urgently needed to reduce the rate of infection in hospitals, as well as for consumers use.
The inclusion of coloring agents in aqueous bleach solutions has previously been described. Due to the strong tendency of bleach solution to oxidize dyes, many have disclosed methods for the incorporation of coloring agents that are stable in bleach. U.S. Pat. No. 4,623,476 to Nayar teaches a method and composition for the stable suspension of pigments in aqueous hypochlorite bleach solutions, using a bleach-stable pigment (Ultramarine Blue), an optical brightener, and a surfactant. U.S. Pat. No. 6,503,877 to Grande teaches a liquid colored thickened bleach composition that includes Ultramarine Blue as a colorant and a viscosifying surfactant that helps provide stable coloration and viscosity upon prolonged periods of storage. U.S. Pat. No. 4,474,677 to Foxlee describes halogenated copper phthalocyanine pigments for forming blue or green aqueous bleaching solutions. These and similar patents solve the problem of rapid bleaching of dyes by strong oxidants by providing more color-stable compositions which retain their color even after prolonged contact with the oxidant.
Oxidizable dyes have been described in the use of cleaning formulations. U.S. Pat. No. 4,308,625 to Kitko discloses the use of bleach-sensitive dyes in combination with hypochlorite sanitizing agents. Kitko describes a toilet bowl sanitizer in which the oxidizable dye and bleach solution are dispensed upon flushing such that the subsequent fading of the color indicates bleaching action. U.S. Pat. No. 6,447,757 to Orlowski discloses the inclusion of FD&C Blue 1 pigment as a component of a bleach-based teeth-whitening mixture. The decolorization of the dye allows the patient to monitor the occurrence and completion of teeth bleaching activity.
U.S. Pat. No. 4,822,854 to Ciolino describes the use of acidifying agents, such as oxalic acid for preventing impurities within the glycol ether-based disinfectant from reacting with and decolorizing the dye at a pH range of 2 to 6.5. The aim is to prevent unwanted impurities within a disinfectant from reacting with the dye.
U.S. Pat. No. 5,110,492 to Casey discloses the combination of a cleaning composition with a disappearing pH dye that must be sealed in an airtight container. Operating under a similar method, U.S. Pat. Application 2014/0057987 by Vinson discloses the composition of a disinfectant with a pH indicator dye and an alkaline substance. The pH dye initially expresses color upon spraying but rapidly fades to clear upon exposure to the sprayed surface and the air.
There remains a need for new compositions and methods to ensure the thorough and efficient disinfection of surfaces. The present invention addresses this need.